Molecular heterogeneity is central to the development of therapeutic resistance in cancer patients. Current pathology practices are not sufficient for analyzing the molecular and functional properties of heterogeneous populations within a tumor. New approaches are needed for obtaining and using this information to guide more effective treatments that anticipate and suppress therapeutic resistance, and that improve the outcome for patients with cancer. Project 4 develops platforms combining nano-, chemical and micro-technologies with biological content to facilitate highly multiplexed quantitative molecular and functional measurements of small tumor samples directiy from the operafing room. The technology mix allows us to perform highly multiplexed biological measurements on small enough samples so that we can effectively address the questions of heterogeneity within solid glioblastoma tumors. The glioblastoma focus of this project permits leveraging the expertise of the investigators and established infrastructure developed during years 1-4 of our CCNE. This infrastructure includes access to meticulously characterized clinical samples, powerful mouse models, and companion grants obtained over the past few years that pave the way for integration of these technologies into the clinic. The technology pathway within this project begins by leveraging off of the platform of DNA encoded anfibody libraries (DEAL) that was developed under current CCNE funding. We extend this platform to a host of new measurement types for analyzing tumor molecular heterogeneity resolved to the single cell level. The biological content makes these platforms clinically relevant and adds significant value for commercialization. We aim to develop technologies and approaches that provide information relevant to the clinical care of GBM pafients, but which should also be broadly applicable to other solid tumor cancers. We have assembled highly cross-disciplinary, interactive team that has several years of experience at working together. Our team bridges from the physical science lab to the oncology clinic.